In 1918 it was shown by one of us1 that a high protein diet over long periods produced in rabbits chronic, diffuse, bilateral kidney lesions. It seemed not improbable, then, to expect some evidence of renal irritation if high protein diets were forced for short periods in those cases where some kidney damage already might exist. In recent years a number of investigators have become more and more convinced that cases of so called essential hypertension were in fact nephritic. Harpuder2 made a careful clinical and anatomic study of cases of essential hypertension and concluded that in every case a persistent hypertension was indicative of chronic nephritis of "arteriosclerotic type." Clinically, out of 504 cases with a systolic blood pressure persistently over 160 mm. mercury, 490, or 97.2 per cent. showed, definite disturbances of kidney function. But this view is not as yet universally accepted. Moschowitz,3 for example, maintains that